Could be because that percentage is wrong. There were two cards cast per voter so actual turnout was 70%

This is the case. Voter turnout was 70%, not 140%. The statistic cited was for "cards cast" not "votes cast." Each ballot had two cards. So if you divide the number of cards cast by the number of eligible voters then you'd get 1.41

Didn't you learn anything in gradeschool math? It's not politically correct to point out math stupidity. It makes kids feel bad, and curbs their imagination and creativity, and might even fester math anxieties.